1. Field of the Invention
The present invention relates to a vehicle suspension member.
2. Description of the Related Art
Vehicles such as cars comprise a suspension mechanism. The suspension mechanism has a shock-absorbing function of suppressing propagation of unevenness of road surfaces to the vehicle body, a function of aligning the wheels and axle, and a function of pressing the wheels against road surfaces, thereby enabling to improve the riding comfort, operation stability and the like. The suspension mechanism comprises various suspension members such as coiled springs, a stabilizer bar and a plate spring.
The coiled spring is placed between a spring seat located at an upper portion of the spring and another spring seat located at a lower portion while being compressed by the weight of the vehicle, and expands/contracts according to the load.
The stabilizer bar provided in the suspension mechanism of a car comprises a torsion portion (twisted portion) extending along the width direction of the car, arm portions connected to respective ends of the torsion portion, and bend portions formed between the torsion portion and the arm portions, respectively. For example, the torsion portion is supported by the vehicle body through a rubber bush and the arm portions are coupled to suspension arms and the like of the suspension mechanism through a stabilizer bar link.
These suspension members including coiled springs and stabilizer bar are usually formed from a spring steel material, and antirust coatings are applied on their surfaces in order to further improve the antirust property. The antirust coating is usually constituted by an epoxy resin-based coating (see, for example, JP 2012-000530 A and WO 2014-013827 A).